In the construction of frame buildings, it is very important that frame walls be constructed such that the components of the frame wall are square. The top framing members should be parallel to the bottom framing members, and the vertical framing members must be perpendicular to the top and bottom framing members. Additionally, openings for window, doors, and other inserted components within the frame wall must be located properly, and the framing components for those openings must be square with the other framing components. Although these framing requirements are common knowledge in the construction industry, it is impractical to design and construct framing jigs for each type and variation of frame wall. Additionally, such a framing jig would not be easily transportable.
To solve this problem, there have been several attempts to invent a device that ensures that frame walls are constructed squarely, that would allow for variations in the design of the frame wall being fabricated, and would be transportable from job site to job site. However, all of these attempts suffer from one of more deficiencies.
Examples of variations for framing fixtures can be found in a number of patents. U.S. Pat. No. 4,154,436 discloses a wall component fabricating jig for building components. The jig includes a wheeled dolly that makes the jig portable. A frame is included that holds the upper and lower longitudinal plate and sill in position. Other holders are positioned on the frame to locate and hold vertical stud members. The clamping mechanism allows for fabrication of walls that vary in height from eight to ten feet. The frame includes a clamping ability that clamps the upper plate and the lower sill against the vertical studs until the frame assembly has been nailed together. After assembly, the wood frame assembly is lifted from the jig by two conveyors and the wood frame assembly is rolled off the jig. All clamping and adjusting parts are controlled by pneumatic devices. However, the device does not include spring loaded vertical stud locators and the clamping operation does not include a rack and pinion assembly for more precise clamping.
U.S. Pat. No. 3,711,007 also discloses a building wall section fabricating machine for fabricating the wall of a building. The jig includes a set of wheels that allow the device to be portable. Longitudinal wood sills and plates are placed in position on the jig, followed by the placement of vertical wall studs using stud placement saddle units. The jig includes several adjustment screws that allow the frame to be adjusted for fabricating walls of varying heights. However, as before, the device does not include any clamping mechanism or spring loaded vertical stud locator pins. Additionally, the assembled wood frame section is removed by a hoist because the jig does not include any devices that allow the assembled wood frame section to be off-loaded from the jig. The device has no rack and pinion assembly for clamping.
The device in U.S. Pat. No. 3,629,931 discloses an apparatus for nailing a structural frame. The device includes a set of axle-mounted wheels that allows the device to be portable. Longitudinal plates and sills are placed on the jig and vertical studs are interspersed between, the studs being located by a series of brackets consisting of two vertical plates. However, there is no adjustment for fabricating wood frame walls of different vertical heights. There are also no spring loaded pins for locating the vertical studs, and there is no apparent clamping capability or rack and pinion assembly for clamping.
Finally, the device in U.S. Pat. No. 3,933,348 discloses a wall framer for use in assembling wall frames. Although the device is intended to be portable, it does not include wheels or axles. Instead, the device is generally collapsible and is transported by a truck or other vehicle. The device does not appear to be capable of adjustment for varying heights of wall frame assemblies. Longitudinal plates and sills are placed on the jig and vertical studs are interspersed between. Although, the vertical studs are located using spring loaded pins, there is no clamping capability to compress the wood frame components together during assembly and there is no rack and pinion assembly.
While all of the above inventions are intended to provide an adjustable, transportable wall framing fixture, all of these devices have at least one significant deficiency that prevents those devices from solving all of the problems with such fixtures.